/* Upsample by a factor 2, coarser */
void SKP_Silk_resample_2_1_coarse(
const SKP_int16 *in, /* I: 8 kHz signal [len] */
SKP_int32 *S, /* I/O: State vector [4] */
SKP_int16 *out, /* O: 16 kHz signal [2*len] */
SKP_int32 *scratch, /* I: Scratch memory [3*len] */
const SKP_int32 len /* I: Number of INPUT samples */
)
{
SKP_int32 k, idx;
/* Coefficients for coarser 2-fold resampling */
const SKP_int16 A20c[ 2 ] = { 2119, 16663 };
const SKP_int16 A21c[ 2 ] = { 8050, 26861 };
/* Convert Q15 -> Q25 */
for( k = 0; k < len; k++ ) {
scratch[ k ] = SKP_LSHIFT( (SKP_int32)in[ k ], 10 );
}
idx = SKP_LSHIFT( len, 1 );
/* Allpass filters */
SKP_Silk_allpass_int( scratch, S, A20c[ 0 ], scratch + idx, len );
SKP_Silk_allpass_int( scratch + idx, S + 1, A20c[ 1 ], scratch + len, len );
SKP_Silk_allpass_int( scratch, S + 2, A21c[ 0 ], scratch + idx, len );
SKP_Silk_allpass_int( scratch + idx, S + 3, A21c[ 1 ], scratch, len );
/* Interleave two allpass outputs */
for( k = 0; k < len; k++ ) {
idx = SKP_LSHIFT( k, 1 );
out[ idx ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( scratch[ k + len ], 10 ) );
out[ idx + 1 ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( scratch[ k ], 10 ) );
}
}
/* Split signal into two decimated bands using first-order allpass filters */
void SKP_Silk_ana_filt_bank_1(const int16_t * in, /* I: Input signal [N] */
int32_t * S, /* I/O: State vector [2] */
int16_t * outL, /* O: Low band [N/2] */
int16_t * outH, /* O: High band [N/2] */
int32_t * scratch, /* I: Scratch memory [3*N/2] */
const int32_t N /* I: Number of input samples */
)
{
int k, N2 = SKP_RSHIFT(N, 1);
int32_t out_tmp;
/* De-interleave three allpass inputs, and convert Q15 -> Q25 */
for (k = 0; k < N2; k++) {
scratch[k + N] = SKP_LSHIFT((int32_t) in[2 * k], 10);
scratch[k + N2] = SKP_LSHIFT((int32_t) in[2 * k + 1], 10);
}
/* Allpass filters */
SKP_Silk_allpass_int(scratch + N2, S + 0, A_fb1_20[0], scratch, N2);
SKP_Silk_allpass_int(scratch + N, S + 1, A_fb1_21[0], scratch + N2, N2);
/* Add and subtract two allpass outputs to create bands */
for (k = 0; k < N2; k++) {
out_tmp = scratch[k] + scratch[k + N2];
outL[k] = (int16_t) SKP_SAT16(SKP_RSHIFT_ROUND(out_tmp, 11));
out_tmp = scratch[k] - scratch[k + N2];
outH[k] = (int16_t) SKP_SAT16(SKP_RSHIFT_ROUND(out_tmp, 11));
}
}
void SKP_Silk_MA_Prediction_Q13(
const SKP_int16 *in, /* I: input signal */
const SKP_int16 *B, /* I: MA prediction coefficients, Q13 [order] */
SKP_int32 *S, /* I/O: state vector [order] */
SKP_int16 *out, /* O: output signal */
SKP_int32 len, /* I: signal length */
SKP_int32 order /* I: filter order */
)
{
SKP_int k, in16;
SKP_int32 out32;
switch(order) {
case 8:
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 13 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 13 );
FILTER_LOOP_ORDER_8(S, B, in16);
out[ k ] = (SKP_int16) SKP_SAT16(out32);
}
break;
case 10:
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 13 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 13 );
FILTER_LOOP_ORDER_10(S, B, in16);
out[ k ] = (SKP_int16) SKP_SAT16(out32);
}
break;
case 12:
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 13 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 13 );
FILTER_LOOP_ORDER_12(S, B, in16);
out[ k ] = (SKP_int16) SKP_SAT16(out32);
}
break;
case 16:
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 13 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 13 );
FILTER_LOOP_ORDER_16(S, B, in16);
out[ k ] = (SKP_int16) SKP_SAT16(out32);
}
break;
default:
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 13 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 13 );
FILTER_LOOP_ORDER_ANY(S, B, in16, order);
out[ k ] = (SKP_int16) SKP_SAT16(out32);
}
}
}
/* Variable order MA prediction error filter */
void SKP_Silk_MA_Prediction(
const SKP_int16 *in, /* I: Input signal */
const SKP_int16 *B, /* I: MA prediction coefficients, Q12 [order] */
SKP_int32 *S, /* I/O: State vector [order] */
SKP_int16 *out, /* O: Output signal */
const SKP_int32 len, /* I: Signal length */
const SKP_int32 order /* I: Filter order */
)
{
SKP_int k, d, in16;
SKP_int32 out32;
SKP_int32 B32;
if( ( order & 1 ) == 0 && (SKP_int32)( (SKP_int_ptr_size)B & 3 ) == 0 ) {
/* Even order and 4-byte aligned coefficient array */
/* NOTE: the code below loads two int16 values in an int32, and multiplies each using the */
/* SMLABB and SMLABT instructions. On a big-endian CPU the two int16 variables would be */
/* loaded in reverse order and the code will give the wrong result. In that case swapping */
/* the SMLABB and SMLABT instructions should solve the problem. */
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 12 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 12 );
for( d = 0; d < order - 2; d += 2 ) {
B32 = *( (SKP_int32*)&B[ d ] ); /* read two coefficients at once */
S[ d ] = SKP_SMLABB_ovflw( S[ d + 1 ], in16, B32 );
S[ d + 1 ] = SKP_SMLABT_ovflw( S[ d + 2 ], in16, B32 );
}
B32 = *( (SKP_int32*)&B[ d ] ); /* read two coefficients at once */
S[ order - 2 ] = SKP_SMLABB_ovflw( S[ order - 1 ], in16, B32 );
S[ order - 1 ] = SKP_SMULBT( in16, B32 );
/* Limit */
out[ k ] = (SKP_int16)SKP_SAT16( out32 );
}
} else {
/* Odd order or not 4-byte aligned coefficient array */
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 12 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 12 );
for( d = 0; d < order - 1; d++ ) {
S[ d ] = SKP_SMLABB_ovflw( S[ d + 1 ], in16, B[ d ] );
}
S[ order - 1 ] = SKP_SMULBB( in16, B[ order - 1 ] );
/* Limit */
out[ k ] = (SKP_int16)SKP_SAT16( out32 );
}
}
}
/* Convert adaptive Mid/Side representation to Left/Right stereo signal */
void silk_stereo_MS_to_LR(
stereo_dec_state *state, /* I/O State */
opus_int16 x1[], /* I/O Left input signal, becomes mid signal */
opus_int16 x2[], /* I/O Right input signal, becomes side signal */
const opus_int32 pred_Q13[], /* I Predictors */
opus_int fs_kHz, /* I Samples rate (kHz) */
opus_int frame_length /* I Number of samples */
)
{
opus_int n, denom_Q16, delta0_Q13, delta1_Q13;
opus_int32 sum, diff, pred0_Q13, pred1_Q13;
/* Buffering */
SKP_memcpy( x1, state->sMid, 2 * sizeof( opus_int16 ) );
SKP_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) );
SKP_memcpy( state->sMid, &x1[ frame_length ], 2 * sizeof( opus_int16 ) );
SKP_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) );
/* Interpolate predictors and add prediction to side channel */
pred0_Q13 = state->pred_prev_Q13[ 0 ];
pred1_Q13 = state->pred_prev_Q13[ 1 ];
denom_Q16 = SKP_DIV32_16( 1 << 16, STEREO_INTERP_LEN_MS * fs_kHz );
delta0_Q13 = SKP_RSHIFT_ROUND( SKP_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 );
delta1_Q13 = SKP_RSHIFT_ROUND( SKP_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 );
for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) {
pred0_Q13 += delta0_Q13;
pred1_Q13 += delta1_Q13;
sum = SKP_LSHIFT( SKP_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */
sum = SKP_SMLAWB( SKP_LSHIFT( ( opus_int32 )x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */
sum = SKP_SMLAWB( sum, SKP_LSHIFT( ( opus_int32 )x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */
x2[ n + 1 ] = (opus_int16)SKP_SAT16( SKP_RSHIFT_ROUND( sum, 8 ) );
}
pred0_Q13 = pred_Q13[ 0 ];
pred1_Q13 = pred_Q13[ 1 ];
for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) {
sum = SKP_LSHIFT( SKP_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */
sum = SKP_SMLAWB( SKP_LSHIFT( ( opus_int32 )x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */
sum = SKP_SMLAWB( sum, SKP_LSHIFT( ( opus_int32 )x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */
x2[ n + 1 ] = (opus_int16)SKP_SAT16( SKP_RSHIFT_ROUND( sum, 8 ) );
}
state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ];
state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ];
/* Convert to left/right signals */
for( n = 0; n < frame_length; n++ ) {
sum = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ];
diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ];
x1[ n + 1 ] = (opus_int16)SKP_SAT16( sum );
x2[ n + 1 ] = (opus_int16)SKP_SAT16( diff );
}
}
/* SKP_Silk_prefilter. Prefilter for finding Quantizer input signal */
SKP_INLINE void SKP_Silk_prefilt_FIX(
SKP_Silk_prefilter_state_FIX *P, /* I/O state */
SKP_int32 st_res_Q12[], /* I short term residual signal */
SKP_int16 xw[], /* O prefiltered signal */
SKP_int32 HarmShapeFIRPacked_Q12, /* I Harmonic shaping coeficients */
SKP_int Tilt_Q14, /* I Tilt shaping coeficient */
SKP_int32 LF_shp_Q14, /* I Low-frequancy shaping coeficients*/
SKP_int lag, /* I Lag for harmonic shaping */
SKP_int length /* I Length of signals */
)
{
SKP_int i, idx, LTP_shp_buf_idx;
SKP_int32 n_LTP_Q12, n_Tilt_Q10, n_LF_Q10;
SKP_int32 sLF_MA_shp_Q12, sLF_AR_shp_Q12;
SKP_int16 *LTP_shp_buf;
/* To speed up use temp variables instead of using the struct */
LTP_shp_buf = P->sLTP_shp;
LTP_shp_buf_idx = P->sLTP_shp_buf_idx;
sLF_AR_shp_Q12 = P->sLF_AR_shp_Q12;
sLF_MA_shp_Q12 = P->sLF_MA_shp_Q12;
for( i = 0; i < length; i++ ) {
if( lag > 0 ) {
/* unrolled loop */
SKP_assert( HARM_SHAPE_FIR_TAPS == 3 );
idx = lag + LTP_shp_buf_idx;
n_LTP_Q12 = SKP_SMULBB( LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 - 1) & LTP_MASK ], HarmShapeFIRPacked_Q12 );
n_LTP_Q12 = SKP_SMLABT( n_LTP_Q12, LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 ) & LTP_MASK ], HarmShapeFIRPacked_Q12 );
n_LTP_Q12 = SKP_SMLABB( n_LTP_Q12, LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 + 1) & LTP_MASK ], HarmShapeFIRPacked_Q12 );
} else {
n_LTP_Q12 = 0;
}
n_Tilt_Q10 = SKP_SMULWB( sLF_AR_shp_Q12, Tilt_Q14 );
n_LF_Q10 = SKP_SMLAWB( SKP_SMULWT( sLF_AR_shp_Q12, LF_shp_Q14 ), sLF_MA_shp_Q12, LF_shp_Q14 );
sLF_AR_shp_Q12 = SKP_SUB32( st_res_Q12[ i ], SKP_LSHIFT( n_Tilt_Q10, 2 ) );
sLF_MA_shp_Q12 = SKP_SUB32( sLF_AR_shp_Q12, SKP_LSHIFT( n_LF_Q10, 2 ) );
LTP_shp_buf_idx = ( LTP_shp_buf_idx - 1 ) & LTP_MASK;
LTP_shp_buf[ LTP_shp_buf_idx ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( sLF_MA_shp_Q12, 12 ) );
xw[i] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SUB32( sLF_MA_shp_Q12, n_LTP_Q12 ), 12 ) );
}
/* Copy temp variable back to state */
P->sLF_AR_shp_Q12 = sLF_AR_shp_Q12;
P->sLF_MA_shp_Q12 = sLF_MA_shp_Q12;
P->sLTP_shp_buf_idx = LTP_shp_buf_idx;
}
/* Downsample by a factor 2, coarsest */
void SKP_Silk_resample_1_2_coarsest(
const SKP_int16 *in, /* I: 16 kHz signal [2*len] */
SKP_int32 *S, /* I/O: State vector [2] */
SKP_int16 *out, /* O: 8 kHz signal [len] */
SKP_int32 *scratch, /* I: Scratch memory [3*len] */
const SKP_int32 len /* I: Number of OUTPUT samples*/
)
{
SKP_int32 k, idx;
/* De-interleave allpass inputs, and convert Q15 -> Q25 */
for( k = 0; k < len; k++ ) {
idx = SKP_LSHIFT( k, 1 );
scratch[ k ] = SKP_LSHIFT( (SKP_int32)in[ idx ], 10 );
scratch[ k + len ] = SKP_LSHIFT( (SKP_int32)in[ idx + 1 ], 10 );
}
idx = SKP_LSHIFT( len, 1 );
/* Allpass filters */
SKP_Silk_allpass_int( scratch, S, A21cst[ 0 ], scratch + idx, len );
SKP_Silk_allpass_int( scratch + len, S + 1, A20cst[ 0 ], scratch, len );
/* Add two allpass outputs */
for( k = 0; k < len; k++ ) {
out[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( scratch[ k ] + scratch[ k + idx ], 11 ) );
}
}
/* Generates excitation for CNG LPC synthesis */
SKP_INLINE void SKP_Silk_CNG_exc(
SKP_int16 residual[], /* O CNG residual signal Q0 */
SKP_int32 exc_buf_Q10[], /* I Random samples buffer Q10 */
SKP_int32 Gain_Q16, /* I Gain to apply */
SKP_int length, /* I Length */
SKP_int32 *rand_seed /* I/O Seed to random index generator */
)
{
SKP_int32 seed;
SKP_int i, idx, exc_mask;
exc_mask = CNG_BUF_MASK_MAX;
while( exc_mask > length ) {
exc_mask = SKP_RSHIFT( exc_mask, 1 );
}
seed = *rand_seed;
for( i = 0; i < length; i++ ) {
seed = SKP_RAND( seed );
idx = ( SKP_int )( SKP_RSHIFT( seed, 24 ) & exc_mask );
SKP_assert( idx >= 0 );
SKP_assert( idx <= CNG_BUF_MASK_MAX );
residual[ i ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SMULWW( exc_buf_Q10[ idx ], Gain_Q16 ), 10 ) );
}
*rand_seed = seed;
}
/*
Variable order MA prediction error filter. Inverse filter of
SKP_Silk_LPC_synthesis_filter.
The inlined assembly makes it over 30% faster than the generic C.
*/
void SKP_Silk_LPC_analysis_filter(
const SKP_int16 *in, /* I: Input signal */
const SKP_int16 *B, /* I: MA prediction coefficients, Q12 [order] */
SKP_int16 *S, /* I/O: State vector [order] */
SKP_int16 *out, /* O: Output signal */
const SKP_int32 len, /* I: Signal length */
const SKP_int32 Order /* I: Filter order */
)
{
SKP_int k;
SKP_int32 out32_Q12, out32;
/* Order must be even */
SKP_assert( 2 * Order_half == Order );
/* S[] values are in Q0 */
for( k = 0; k < len; k++ ) {
LPC_ANALYSYS(out32_Q12, S, B, Order);
/* Subtract prediction */
out32_Q12 = SKP_SUB_SAT32( SKP_LSHIFT(
(SKP_int32)in[ k ], 12 ), out32_Q12 );
/* Scale to Q0 */
out32 = SKP_RSHIFT_ROUND( out32_Q12, 12 );
out[ k ] = (SKP_int16)SKP_SAT16( out32 );
/* Move input line */
S[ 0 ] = in[ k ];
}
}
/* Variable order MA prediction error filter */
void SKP_Silk_MA_Prediction(
const SKP_int16 *in, /* I: Input signal */
const SKP_int16 *B, /* I: MA prediction coefficients, Q12 [order] */
SKP_int32 *S, /* I/O: State vector [order] */
SKP_int16 *out, /* O: Output signal */
const SKP_int32 len, /* I: Signal length */
const SKP_int32 order /* I: Filter order */
)
{
SKP_int k, d, in16;
SKP_int32 out32;
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_LSHIFT( in16, 12 ) - S[ 0 ];
out32 = SKP_RSHIFT_ROUND( out32, 12 );
for( d = 0; d < order - 1; d++ ) {
S[ d ] = SKP_SMLABB_ovflw( S[ d + 1 ], in16, B[ d ] );
}
S[ order - 1 ] = SKP_SMULBB( in16, B[ order - 1 ] );
/* Limit */
out[ k ] = (SKP_int16)SKP_SAT16( out32 );
}
}
/* Resamples by a factor 3/1 */
void SKP_Silk_resample_3_1(
SKP_int16 *out, /* O: Fs_high signal [inLen*3] */
SKP_int32 *S, /* I/O: State vector [7] */
const SKP_int16 *in, /* I: Fs_low signal [inLen] */
const SKP_int32 inLen /* I: Input length */
)
{
SKP_int k, LSubFrameIn, LSubFrameOut;
SKP_int32 out_tmp, idx, inLenTmp = inLen;
SKP_int32 scratch00[ IN_SUBFR_LEN_RESAMPLE_3_1 ];
SKP_int32 scratch0[ 3 * IN_SUBFR_LEN_RESAMPLE_3_1 ];
SKP_int32 scratch1[ 3 * IN_SUBFR_LEN_RESAMPLE_3_1 ];
/* Coefficients for 3-fold resampling */
const SKP_int16 A30[ 2 ] = { 1773, 17818 };
const SKP_int16 A31[ 2 ] = { 4942, 25677 };
const SKP_int16 A32[ 2 ] = { 11786, 29304 };
while( inLenTmp > 0 ) {
LSubFrameIn = SKP_min_int( IN_SUBFR_LEN_RESAMPLE_3_1, inLenTmp );
LSubFrameOut = SKP_SMULBB( 3, LSubFrameIn );
/* Convert Q15 -> Q25 */
for( k = 0; k < LSubFrameIn; k++ ) {
scratch00[k] = SKP_LSHIFT( (SKP_int32)in[ k ], 10 );
}
/* Allpass filtering */
/* Scratch size: 2 * 3* LSubFrame * sizeof(SKP_int32) */
SKP_Silk_allpass_int( scratch00, S + 1, A30[ 0 ], scratch1, LSubFrameIn );
SKP_Silk_allpass_int( scratch1, S + 2, A30[ 1 ], scratch0, LSubFrameIn );
SKP_Silk_allpass_int( scratch00, S + 3, A31[ 0 ], scratch1, LSubFrameIn );
SKP_Silk_allpass_int( scratch1, S + 4, A31[ 1 ], scratch0 + IN_SUBFR_LEN_RESAMPLE_3_1, LSubFrameIn );
SKP_Silk_allpass_int( scratch00, S + 5, A32[ 0 ], scratch1, LSubFrameIn );
SKP_Silk_allpass_int( scratch1, S + 6, A32[ 1 ], scratch0 + 2 * IN_SUBFR_LEN_RESAMPLE_3_1, LSubFrameIn );
/* Interleave three allpass outputs */
for( k = 0; k < LSubFrameIn; k++ ) {
idx = SKP_SMULBB( 3, k );
scratch1[ idx ] = scratch0[ k ];
scratch1[ idx + 1 ] = scratch0[ k + IN_SUBFR_LEN_RESAMPLE_3_1 ];
scratch1[ idx + 2 ] = scratch0[ k + 2 * IN_SUBFR_LEN_RESAMPLE_3_1 ];
}
/* Low-pass filtering */
SKP_Silk_lowpass_int( scratch1, S, scratch0, LSubFrameOut );
/* Saturate and convert to SKP_int16 */
for( k = 0; k < LSubFrameOut; k++ ) {
out_tmp = scratch0[ k ];
out[ k ] = (SKP_int16) SKP_SAT16( SKP_RSHIFT_ROUND( out_tmp, 10 ) );
}
in += LSubFrameIn;
inLenTmp -= LSubFrameIn;
out += LSubFrameOut;
}
}
/* Variable order MA filter */
void SKP_Silk_MA(
const SKP_int16 *in, /* I: input signal */
const SKP_int16 *B, /* I: MA coefficients, Q13 [order+1] */
SKP_int32 *S, /* I/O: state vector [order] */
SKP_int16 *out, /* O: output signal */
const SKP_int32 len, /* I: signal length */
const SKP_int32 order /* I: filter order */
)
{
SKP_int k, d, in16;
SKP_int32 out32;
for( k = 0; k < len; k++ ) {
in16 = in[ k ];
out32 = SKP_SMLABB( S[ 0 ], in16, B[ 0 ] );
out32 = SKP_RSHIFT_ROUND( out32, 13 );
for( d = 1; d < order; d++ ) {
S[ d - 1 ] = SKP_SMLABB( S[ d ], in16, B[ d ] );
}
S[ order - 1 ] = SKP_SMULBB( in16, B[ order ] );
/* Limit */
out[ k ] = (SKP_int16)SKP_SAT16( out32 );
}
}
/* Can handle slowly varying filter coefficients */
void SKP_Silk_biquad(
const SKP_int16 *in, /* I: input signal */
const SKP_int16 *B, /* I: MA coefficients, Q13 [3] */
const SKP_int16 *A, /* I: AR coefficients, Q13 [2] */
SKP_int32 *S, /* I/O: state vector [2] */
SKP_int16 *out, /* O: output signal */
const SKP_int32 len /* I: signal length */
)
{
SKP_int k, in16;
SKP_int32 A0_neg, A1_neg, S0, S1, out32, tmp32;
S0 = S[ 0 ];
S1 = S[ 1 ];
A0_neg = -A[ 0 ];
A1_neg = -A[ 1 ];
for( k = 0; k < len; k++ ) {
/* S[ 0 ], S[ 1 ]: Q13 */
in16 = in[ k ];
out32 = SKP_SMLABB( S0, in16, B[ 0 ] );
S0 = SKP_SMLABB( S1, in16, B[ 1 ] );
S0 += SKP_LSHIFT( SKP_SMULWB( out32, A0_neg ), 3 );
S1 = SKP_LSHIFT( SKP_SMULWB( out32, A1_neg ), 3 );
S1 = SKP_SMLABB( S1, in16, B[ 2 ] );
tmp32 = SKP_RSHIFT_ROUND( out32, 13 ) + 1;
out[ k ] = (SKP_int16)SKP_SAT16( tmp32 );
}
S[ 0 ] = S0;
S[ 1 ] = S1;
}
SKP_INLINE SKP_int16 *SKP_Silk_resampler_private_down_FIR_INTERPOL1(
SKP_int16 *out, SKP_int32 *buf2, const SKP_int16 *FIR_Coefs, SKP_int32 max_index_Q16, SKP_int32 index_increment_Q16, SKP_int32 FIR_Fracs){
SKP_int32 index_Q16, res_Q6;
SKP_int32 *buf_ptr;
SKP_int32 interpol_ind;
const SKP_int16 *interpol_ptr;
for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
/* Integer part gives pointer to buffered input */
buf_ptr = buf2 + SKP_RSHIFT( index_Q16, 16 );
/* Fractional part gives interpolation coefficients */
interpol_ind = SKP_SMULWB( index_Q16 & 0xFFFF, FIR_Fracs );
/* Inner product */
interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR / 2 * interpol_ind ];
res_Q6 = SKP_SMULWB( buf_ptr[ 0 ], interpol_ptr[ 0 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 1 ], interpol_ptr[ 1 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 2 ], interpol_ptr[ 2 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 3 ], interpol_ptr[ 3 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 4 ], interpol_ptr[ 4 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 5 ], interpol_ptr[ 5 ] );
interpol_ptr = &FIR_Coefs[ RESAMPLER_DOWN_ORDER_FIR / 2 * ( FIR_Fracs - 1 - interpol_ind ) ];
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 11 ], interpol_ptr[ 0 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 10 ], interpol_ptr[ 1 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 9 ], interpol_ptr[ 2 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 8 ], interpol_ptr[ 3 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 7 ], interpol_ptr[ 4 ] );
res_Q6 = SKP_SMLAWB( res_Q6, buf_ptr[ 6 ], interpol_ptr[ 5 ] );
/* Scale down, saturate and store in output array */
*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q6, 6 ) );
}
return out;
}
/* Processing of gains */
void silk_process_gains_FIX(
silk_encoder_state_FIX *psEnc, /* I/O Encoder state_FIX */
silk_encoder_control_FIX *psEncCtrl /* I/O Encoder control_FIX */
)
{
silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
opus_int k;
opus_int32 s_Q16, InvMaxSqrVal_Q16, gain, gain_squared, ResNrg, ResNrgPart, quant_offset_Q10;
/* Gain reduction when LTP coding gain is high */
if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
/*s = -0.5f * SKP_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */
s_Q16 = -silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->LTPredCodGain_Q7 - SILK_FIX_CONST( 12.0, 7 ), 4 ) );
for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
psEncCtrl->Gains_Q16[ k ] = SKP_SMLAWB( psEncCtrl->Gains_Q16[ k ], psEncCtrl->Gains_Q16[ k ], s_Q16 );
}
}
/* Limit the quantized signal */
/* InvMaxSqrVal = pow( 2.0f, 0.33f * ( 21.0f - SNR_dB ) ) / subfr_length; */
InvMaxSqrVal_Q16 = SKP_DIV32_16( silk_log2lin(
SKP_SMULWB( SILK_FIX_CONST( 21 + 16 / 0.33, 7 ) - psEnc->sCmn.SNR_dB_Q7, SILK_FIX_CONST( 0.33, 16 ) ) ), psEnc->sCmn.subfr_length );
for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
/* Soft limit on ratio residual energy and squared gains */
ResNrg = psEncCtrl->ResNrg[ k ];
ResNrgPart = SKP_SMULWW( ResNrg, InvMaxSqrVal_Q16 );
if( psEncCtrl->ResNrgQ[ k ] > 0 ) {
ResNrgPart = SKP_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] );
} else {
if( ResNrgPart >= SKP_RSHIFT( SKP_int32_MAX, -psEncCtrl->ResNrgQ[ k ] ) ) {
ResNrgPart = SKP_int32_MAX;
} else {
ResNrgPart = SKP_LSHIFT( ResNrgPart, -psEncCtrl->ResNrgQ[ k ] );
}
}
gain = psEncCtrl->Gains_Q16[ k ];
gain_squared = SKP_ADD_SAT32( ResNrgPart, SKP_SMMUL( gain, gain ) );
if( gain_squared < SKP_int16_MAX ) {
/* recalculate with higher precision */
gain_squared = SKP_SMLAWW( SKP_LSHIFT( ResNrgPart, 16 ), gain, gain );
SKP_assert( gain_squared > 0 );
gain = silk_SQRT_APPROX( gain_squared ); /* Q8 */
gain = SKP_min( gain, SKP_int32_MAX >> 8 );
psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 8 ); /* Q16 */
} else {
/* Inverse filter of SKP_Silk_LPC_synthesis_filter */
void SKP_Silk_LPC_analysis_filter(
const SKP_int16 *in, /* I: Input signal */
const SKP_int16 *B, /* I: MA prediction coefficients, Q12 [order] */
SKP_int16 *S, /* I/O: State vector [order] */
SKP_int16 *out, /* O: Output signal */
const SKP_int32 len, /* I: Signal length */
const SKP_int32 Order /* I: Filter order */
)
{
SKP_int k, j, idx, Order_half = SKP_RSHIFT( Order, 1 );
SKP_int32 Btmp, B_align_Q12[ SigProc_MAX_ORDER_LPC >> 1 ], out32_Q12, out32;
SKP_int16 SA, SB;
/* Order must be even */
SKP_assert( 2 * Order_half == Order );
/* Combine two A_Q12 values and ensure 32-bit alignment */
for( k = 0; k < Order_half; k++ ) {
idx = SKP_SMULBB( 2, k );
B_align_Q12[ k ] = ( ( (SKP_int32)B[ idx ] ) & 0x0000ffff ) | SKP_LSHIFT( (SKP_int32)B[ idx + 1 ], 16 );
}
/* S[] values are in Q0 */
for( k = 0; k < len; k++ ) {
SA = S[ 0 ];
out32_Q12 = 0;
for( j = 0; j < ( Order_half - 1 ); j++ ) {
idx = SKP_SMULBB( 2, j ) + 1;
/* Multiply-add two prediction coefficients for each loop */
Btmp = B_align_Q12[ j ];
SB = S[ idx ];
S[ idx ] = SA;
out32_Q12 = SKP_SMLABB( out32_Q12, SA, Btmp );
out32_Q12 = SKP_SMLABT( out32_Q12, SB, Btmp );
SA = S[ idx + 1 ];
S[ idx + 1 ] = SB;
}
/* Unrolled loop: epilog */
Btmp = B_align_Q12[ Order_half - 1 ];
SB = S[ Order - 1 ];
S[ Order - 1 ] = SA;
out32_Q12 = SKP_SMLABB( out32_Q12, SA, Btmp );
out32_Q12 = SKP_SMLABT( out32_Q12, SB, Btmp );
/* Subtract prediction */
out32_Q12 = SKP_SUB_SAT32( SKP_LSHIFT( (SKP_int32)in[ k ], 12 ), out32_Q12 );
/* Scale to Q0 */
out32 = SKP_RSHIFT_ROUND( out32_Q12, 12 );
/* Saturate output */
out[ k ] = (SKP_int16)SKP_SAT16( out32 );
/* Move input line */
S[ 0 ] = in[ k ];
}
}
/* Upsample using a combination of allpass-based 2x upsampling and FIR interpolation */
void SKP_Silk_resampler_private_IIR_FIR(
void *SS, /* I/O: Resampler state */
SKP_int16 out[], /* O: Output signal */
const SKP_int16 in[], /* I: Input signal */
SKP_int32 inLen /* I: Number of input samples */
)
{
SKP_Silk_resampler_state_struct *S = (SKP_Silk_resampler_state_struct *)SS;
SKP_int32 nSamplesIn, table_index;
SKP_int32 max_index_Q16, index_Q16, index_increment_Q16, res_Q15;
SKP_int16 buf[ 2 * RESAMPLER_MAX_BATCH_SIZE_IN + RESAMPLER_ORDER_FIR_144 ];
SKP_int16 *buf_ptr;
/* Copy buffered samples to start of buffer */
SKP_memcpy( buf, S->sFIR, RESAMPLER_ORDER_FIR_144 * sizeof( SKP_int32 ) );
/* Iterate over blocks of frameSizeIn input samples */
index_increment_Q16 = S->invRatio_Q16;
while( 1 ) {
nSamplesIn = SKP_min( inLen, S->batchSize );
if( S->input2x == 1 ) {
/* Upsample 2x */
S->up2_function( S->sIIR, &buf[ RESAMPLER_ORDER_FIR_144 ], in, nSamplesIn );
} else {
/* Fourth-order ARMA filter */
SKP_Silk_resampler_private_ARMA4( S->sIIR, &buf[ RESAMPLER_ORDER_FIR_144 ], in, S->Coefs, nSamplesIn );
}
max_index_Q16 = SKP_LSHIFT32( nSamplesIn, 16 + S->input2x ); /* +1 if 2x upsampling */
/* Interpolate upsampled signal and store in output array */
for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
table_index = SKP_SMULWB( index_Q16 & 0xFFFF, 144 );
buf_ptr = &buf[ index_Q16 >> 16 ];
res_Q15 = SKP_SMULBB( buf_ptr[ 0 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 0 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 1 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 1 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 2 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 2 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 3 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 2 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 4 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 1 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 5 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 0 ] );
*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q15, 15 ) );
}
in += nSamplesIn;
inLen -= nSamplesIn;
if( inLen > 0 ) {
/* More iterations to do; copy last part of filtered signal to beginning of buffer */
SKP_memcpy( buf, &buf[ nSamplesIn << S->input2x ], RESAMPLER_ORDER_FIR_144 * sizeof( SKP_int32 ) );
} else {
break;
}
}
/* Copy last part of filtered signal to the state for the next call */
SKP_memcpy( S->sFIR, &buf[nSamplesIn << S->input2x ], RESAMPLER_ORDER_FIR_144 * sizeof( SKP_int32 ) );
}
void SKP_Silk_LTP_scale_ctrl_FIX(
SKP_Silk_encoder_state_FIX *psEnc, /* I/O encoder state FIX */
SKP_Silk_encoder_control_FIX *psEncCtrl /* I/O encoder control FIX */
)
{
SKP_int round_loss, frames_per_packet;
SKP_int g_out_Q5, g_limit_Q15, thrld1_Q15, thrld2_Q15;
/* 1st order high-pass filter */
psEnc->HPLTPredCodGain_Q7 = SKP_max_int( psEncCtrl->LTPredCodGain_Q7 - psEnc->prevLTPredCodGain_Q7, 0 )
+ SKP_RSHIFT_ROUND( psEnc->HPLTPredCodGain_Q7, 1 );
psEnc->prevLTPredCodGain_Q7 = psEncCtrl->LTPredCodGain_Q7;
/* combine input and filtered input */
g_out_Q5 = SKP_RSHIFT_ROUND( SKP_RSHIFT( psEncCtrl->LTPredCodGain_Q7, 1 ) + SKP_RSHIFT( psEnc->HPLTPredCodGain_Q7, 1 ), 3 );
g_limit_Q15 = SKP_Silk_sigm_Q15( g_out_Q5 - ( 3 << 5 ) );
/* Default is minimum scaling */
psEncCtrl->sCmn.LTP_scaleIndex = 0;
/* Round the loss measure to whole pct */
round_loss = ( SKP_int )psEnc->sCmn.PacketLoss_perc;
/* Only scale if first frame in packet 0% */
if( psEnc->sCmn.nFramesInPayloadBuf == 0 ) {
frames_per_packet = SKP_DIV32_16( psEnc->sCmn.PacketSize_ms, FRAME_LENGTH_MS );
round_loss += frames_per_packet - 1;
thrld1_Q15 = LTPScaleThresholds_Q15[ SKP_min_int( round_loss, NB_THRESHOLDS - 1 ) ];
thrld2_Q15 = LTPScaleThresholds_Q15[ SKP_min_int( round_loss + 1, NB_THRESHOLDS - 1 ) ];
if( g_limit_Q15 > thrld1_Q15 ) {
/* Maximum scaling */
psEncCtrl->sCmn.LTP_scaleIndex = 2;
} else if( g_limit_Q15 > thrld2_Q15 ) {
/* Medium scaling */
psEncCtrl->sCmn.LTP_scaleIndex = 1;
}
}
psEncCtrl->LTP_scale_Q14 = SKP_Silk_LTPScales_table_Q14[ psEncCtrl->sCmn.LTP_scaleIndex ];
}
void SKP_Silk_shell_insertion_sort_increasing(
SKP_int32 *a, /* I/O: Unsorted / Sorted vector */
SKP_int *index, /* O: Index vector for the sorted elements */
const SKP_int L, /* I: Vector length */
const SKP_int K /* I: Number of correctly sorted positions */
)
{
SKP_int32 value, inc_Q16_tmp;
SKP_int i, j, inc, idx;
/* Safety checks */
SKP_assert( K > 0 );
SKP_assert( L > 0 );
SKP_assert( L >= K );
/* Calculate initial step size */
inc_Q16_tmp = SKP_LSHIFT( (SKP_int32)L, 15 );
inc = SKP_RSHIFT( inc_Q16_tmp, 16 );
/* Write start indices in index vector */
for( i = 0; i < K; i++ ) {
index[ i ] = i;
}
/* Shell sort first values */
while( inc > 0 ) {
for( i = inc; i < K; i++ ) {
value = a[ i ];
idx = index[ i ];
for( j = i - inc; ( j >= 0 ) && ( value < a[ j ] ); j -= inc ) {
a[ j + inc ] = a[ j ]; /* Shift value */
index[ j + inc ] = index[ j ]; /* Shift index */
}
a[ j + inc ] = value; /* Write value */
index[ j + inc ] = idx; /* Write index */
}
inc_Q16_tmp = SKP_SMULWB( inc_Q16_tmp, 29789 ); // 29789_Q16 = 2.2^(-1)_Q0
inc = SKP_RSHIFT_ROUND( inc_Q16_tmp, 16 );
}
/* If less than L values are asked for, check the remaining values, */
/* but only spend CPU to ensure that the K first values are correct */
/* Insertion sort remaining values */
for( i = K; i < L; i++ ) {
value = a[ i ];
if( value < a[ K - 1 ] ) {
for( j = K - 2; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {
a[ j + 1 ] = a[ j ]; /* Shift value */
index[ j + 1 ] = index[ j ]; /* Shift index */
}
a[ j + 1 ] = value; /* Write value */
index[ j + 1 ] = i; /* Write index */
}
}
}
void SKP_Silk_LTP_analysis_filter_FIX(
SKP_int16 *LTP_res, /* O: LTP residual signal of length NB_SUBFR * ( pre_length + subfr_length ) */
const SKP_int16 *x, /* I: Pointer to input signal with at least max( pitchL ) preceeding samples */
const SKP_int16 LTPCoef_Q14[ LTP_ORDER * NB_SUBFR ],/* I: LTP_ORDER LTP coefficients for each NB_SUBFR subframe */
const SKP_int pitchL[ NB_SUBFR ], /* I: Pitch lag, one for each subframe */
const SKP_int32 invGains_Qxx[ NB_SUBFR ], /* I: Inverse quantization gains, one for each subframe */
const SKP_int Qxx, /* I: Inverse quantization gains Q domain */
const SKP_int subfr_length, /* I: Length of each subframe */
const SKP_int pre_length /* I: Length of the preceeding samples starting at &x[0] for each subframe */
)
{
const SKP_int16 *x_ptr, *x_lag_ptr;
SKP_int16 Btmp_Q14[ LTP_ORDER ];
SKP_int16 *LTP_res_ptr;
SKP_int k, i, j;
SKP_int32 LTP_est;
x_ptr = x;
LTP_res_ptr = LTP_res;
for( k = 0; k < NB_SUBFR; k++ ) {
x_lag_ptr = x_ptr - pitchL[ k ];
for( i = 0; i < LTP_ORDER; i++ ) {
Btmp_Q14[ i ] = LTPCoef_Q14[ k * LTP_ORDER + i ];
}
/* LTP analysis FIR filter */
for( i = 0; i < subfr_length + pre_length; i++ ) {
LTP_res_ptr[ i ] = x_ptr[ i ];
/* Long-term prediction */
LTP_est = SKP_SMULBB( x_lag_ptr[ LTP_ORDER / 2 ], Btmp_Q14[ 0 ] );
for( j = 1; j < LTP_ORDER; j++ ) {
LTP_est = SKP_SMLABB_ovflw( LTP_est, x_lag_ptr[ LTP_ORDER / 2 - j ], Btmp_Q14[ j ] );
}
LTP_est = SKP_RSHIFT_ROUND( LTP_est, 14 ); // round and -> Q0
/* Subtract long-term prediction */
LTP_res_ptr[ i ] = ( SKP_int16 )SKP_SAT16( ( SKP_int32 )x_ptr[ i ] - LTP_est );
/* Scale residual */
if( Qxx == 16 ) {
LTP_res_ptr[ i ] = SKP_SMULWB( invGains_Qxx[ k ], LTP_res_ptr[ i ] );
} else {
LTP_res_ptr[ i ] = ( SKP_int16 )SKP_CHECK_FIT16( SKP_RSHIFT64( SKP_SMULL( invGains_Qxx[ k ], LTP_res_ptr[ i ] ), Qxx ) );
}
x_lag_ptr++;
}
/* Update pointers */
LTP_res_ptr += subfr_length + pre_length;
x_ptr += subfr_length;
}
}
/* Upsample by a factor 4, Note: very low quality, only use with output sampling rates above 96 kHz. */
void SKP_Silk_resampler_private_up4(
SKP_int32 *S, /* I/O: State vector [ 2 ] */
SKP_int16 *out, /* O: Output signal [ 4 * len ] */
const SKP_int16 *in, /* I: Input signal [ len ] */
SKP_int32 len /* I: Number of INPUT samples */
)
{
SKP_int32 k;
SKP_int32 in32, out32, Y, X;
SKP_int16 out16;
SKP_assert( SKP_Silk_resampler_up2_lq_0 > 0 );
SKP_assert( SKP_Silk_resampler_up2_lq_1 < 0 );
/* Internal variables and state are in Q10 format */
for( k = 0; k < len; k++ ) {
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ k ], 10 );
/* All-pass section for even output sample */
Y = SKP_SUB32( in32, S[ 0 ] );
X = SKP_SMULWB( Y, SKP_Silk_resampler_up2_lq_0 );
out32 = SKP_ADD32( S[ 0 ], X );
S[ 0 ] = SKP_ADD32( in32, X );
/* Convert back to int16 and store to output */
out16 = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( out32, 10 ) );
out[ 4 * k ] = out16;
out[ 4 * k + 1 ] = out16;
/* All-pass section for odd output sample */
Y = SKP_SUB32( in32, S[ 1 ] );
X = SKP_SMLAWB( Y, Y, SKP_Silk_resampler_up2_lq_1 );
out32 = SKP_ADD32( S[ 1 ], X );
S[ 1 ] = SKP_ADD32( in32, X );
/* Convert back to int16 and store to output */
out16 = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( out32, 10 ) );
out[ 4 * k + 2 ] = out16;
out[ 4 * k + 3 ] = out16;
}
}
/* Downsample by a factor 3, low quality */
void SKP_Silk_resampler_down3(
SKP_int32 *S, /* I/O: State vector [ 8 ] */
SKP_int16 *out, /* O: Output signal [ floor(inLen/3) ] */
const SKP_int16 *in, /* I: Input signal [ inLen ] */
SKP_int32 inLen /* I: Number of input samples */
)
{
SKP_int32 nSamplesIn, counter, res_Q6;
SKP_int32 buf[ RESAMPLER_MAX_BATCH_SIZE_IN + ORDER_FIR ];
SKP_int32 *buf_ptr;
/* Copy buffered samples to start of buffer */
SKP_memcpy( buf, S, ORDER_FIR * sizeof( SKP_int32 ) );
/* Iterate over blocks of frameSizeIn input samples */
while( 1 ) {
nSamplesIn = SKP_min( inLen, RESAMPLER_MAX_BATCH_SIZE_IN );
/* Second-order AR filter (output in Q8) */
SKP_Silk_resampler_private_AR2( &S[ ORDER_FIR ], &buf[ ORDER_FIR ], in,
SKP_Silk_Resampler_1_3_COEFS_LQ, nSamplesIn );
/* Interpolate filtered signal */
buf_ptr = buf;
counter = nSamplesIn;
while( counter > 2 ) {
/* Inner product */
res_Q6 = SKP_SMULWB( SKP_ADD32( buf_ptr[ 0 ], buf_ptr[ 5 ] ), SKP_Silk_Resampler_1_3_COEFS_LQ[ 2 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 1 ], buf_ptr[ 4 ] ), SKP_Silk_Resampler_1_3_COEFS_LQ[ 3 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 2 ], buf_ptr[ 3 ] ), SKP_Silk_Resampler_1_3_COEFS_LQ[ 4 ] );
/* Scale down, saturate and store in output array */
*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q6, 6 ) );
buf_ptr += 3;
counter -= 3;
}
in += nSamplesIn;
inLen -= nSamplesIn;
if( inLen > 0 ) {
/* More iterations to do; copy last part of filtered signal to beginning of buffer */
SKP_memcpy( buf, &buf[ nSamplesIn ], ORDER_FIR * sizeof( SKP_int32 ) );
} else {
break;
}
}
/* Copy last part of filtered signal to the state for the next call */
SKP_memcpy( S, &buf[ nSamplesIn ], ORDER_FIR * sizeof( SKP_int32 ) );
}
void SKP_Silk_noise_shape_analysis_FIX(
SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */
SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */
const SKP_int16 *pitch_res, /* I LPC residual from pitch analysis */
const SKP_int16 *x /* I Input signal [ frame_length + la_shape ] */
)
{
SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
SKP_int k, i, nSamples, Qnrg, b_Q14, warping_Q16, scale = 0;
SKP_int32 SNR_adj_dB_Q7, HarmBoost_Q16, HarmShapeGain_Q16, Tilt_Q16, tmp32;
SKP_int32 nrg, pre_nrg_Q30, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7;
SKP_int32 delta_Q16, BWExp1_Q16, BWExp2_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8;
SKP_int32 auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ];
SKP_int32 refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ];
SKP_int32 AR1_Q24[ MAX_SHAPE_LPC_ORDER ];
SKP_int32 AR2_Q24[ MAX_SHAPE_LPC_ORDER ];
SKP_int16 x_windowed[ SHAPE_LPC_WIN_MAX ];
SKP_int32 sqrt_nrg[ MAX_NB_SUBFR ], Qnrg_vec[ MAX_NB_SUBFR ];
const SKP_int16 *x_ptr, *pitch_res_ptr;
/* Point to start of first LPC analysis block */
x_ptr = x - psEnc->sCmn.la_shape;
/****************/
/* CONTROL SNR */
/****************/
/* Reduce SNR_dB values if recent bitstream has exceeded TargetRate */
psEncCtrl->current_SNR_dB_Q7 = psEnc->SNR_dB_Q7 - SKP_SMULBB( psEnc->BufferedInChannel_ms, SKP_FIX_CONST( 0.1, 7 ) );
/* Reduce SNR_dB because of any inband FEC used */
psEncCtrl->current_SNR_dB_Q7 -= psEnc->inBandFEC_SNR_comp_Q7;
/****************/
/* GAIN CONTROL */
/****************/
/* Input quality is the average of the quality in the lowest two VAD bands */
psEncCtrl->input_quality_Q14 = ( SKP_int )SKP_RSHIFT( ( SKP_int32 )psEnc->sCmn.input_quality_bands_Q15[ 0 ]
+ psEnc->sCmn.input_quality_bands_Q15[ 1 ], 2 );
/* Coding quality level, between 0.0_Q0 and 1.0_Q0, but in Q14 */
psEncCtrl->coding_quality_Q14 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->current_SNR_dB_Q7 -
SKP_FIX_CONST( 18.0, 7 ), 4 ) ), 1 );
/* Reduce coding SNR during low speech activity */
SNR_adj_dB_Q7 = psEncCtrl->current_SNR_dB_Q7;
if( psEnc->sCmn.useCBR == 0 ) {
b_Q8 = SKP_FIX_CONST( 1.0, 8 ) - psEnc->sCmn.speech_activity_Q8;
b_Q8 = SKP_SMULWB( SKP_LSHIFT( b_Q8, 8 ), b_Q8 );
SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7,
SKP_SMULBB( SKP_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ), // Q11
SKP_SMULWB( SKP_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) ); // Q12
}
/* Chirp (bandwidth expand) LP AR filter */
void SKP_Silk_bwexpander(int16_t * ar, /* I/O AR filter to be expanded (without leading 1) */
const int d, /* I Length of ar */
int32_t chirp_Q16 /* I Chirp factor (typically in the range 0 to 1) */
)
{
int i;
int32_t chirp_minus_one_Q16;
chirp_minus_one_Q16 = chirp_Q16 - 65536;
/* NB: Dont use SKP_SMULWB, instead of SKP_RSHIFT_ROUND( SKP_MUL() , 16 ), below. */
/* Bias in SKP_SMULWB can lead to unstable filters */
for (i = 0; i < d - 1; i++) {
ar[i] =
(int16_t) SKP_RSHIFT_ROUND(SKP_MUL(chirp_Q16, ar[i]), 16);
chirp_Q16 +=
SKP_RSHIFT_ROUND(SKP_MUL(chirp_Q16, chirp_minus_one_Q16),
16);
}
ar[d - 1] =
(int16_t) SKP_RSHIFT_ROUND(SKP_MUL(chirp_Q16, ar[d - 1]), 16);
}
/* Split signal into two decimated bands using first-order allpass filters */
void SKP_Silk_ana_filt_bank_1(
const SKP_int16 *in, /* I: Input signal [N] */
SKP_int32 *S, /* I/O: State vector [2] */
SKP_int16 *outL, /* O: Low band [N/2] */
SKP_int16 *outH, /* O: High band [N/2] */
SKP_int32 *scratch, /* I: Scratch memory [3*N/2] */ // todo: remove - no longer used
const SKP_int32 N /* I: Number of input samples */
)
{
SKP_int k, N2 = SKP_RSHIFT( N, 1 );
SKP_int32 in32, X, Y, out_1, out_2;
/* Internal variables and state are in Q10 format */
for( k = 0; k < N2; k++ ) {
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ 2 * k ], 10 );
/* All-pass section for even input sample */
Y = SKP_SUB32( in32, S[ 0 ] );
X = SKP_SMLAWB( Y, Y, A_fb1_21[ 0 ] );
out_1 = SKP_ADD32( S[ 0 ], X );
S[ 0 ] = SKP_ADD32( in32, X );
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ 2 * k + 1 ], 10 );
/* All-pass section for odd input sample */
Y = SKP_SUB32( in32, S[ 1 ] );
X = SKP_SMULWB( Y, A_fb1_20[ 0 ] );
out_2 = SKP_ADD32( S[ 1 ], X );
S[ 1 ] = SKP_ADD32( in32, X );
/* Add/subtract, convert back to int16 and store to output */
outL[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( SKP_ADD32( out_2, out_1 ), 11 ) );
outH[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SUB32( out_2, out_1 ), 11 ) );
}
}
/* Second order ARMA filter, alternative implementation */
void SKP_Silk_biquad_alt(
const SKP_int16 *in, /* I: Input signal */
const SKP_int32 *B_Q28, /* I: MA coefficients [3] */
const SKP_int32 *A_Q28, /* I: AR coefficients [2] */
SKP_int32 *S, /* I/O: State vector [2] */
SKP_int16 *out, /* O: Output signal */
const SKP_int32 len /* I: Signal length (must be even) */
)
{
/* DIRECT FORM II TRANSPOSED (uses 2 element state vector) */
SKP_int k;
SKP_int32 inval, A0_U_Q28, A0_L_Q28, A1_U_Q28, A1_L_Q28, out32_Q14;
/* Negate A_Q28 values and split in two parts */
A0_L_Q28 = ( -A_Q28[ 0 ] ) & 0x00003FFF; /* lower part */
A0_U_Q28 = SKP_RSHIFT( -A_Q28[ 0 ], 14 ); /* upper part */
A1_L_Q28 = ( -A_Q28[ 1 ] ) & 0x00003FFF; /* lower part */
A1_U_Q28 = SKP_RSHIFT( -A_Q28[ 1 ], 14 ); /* upper part */
for( k = 0; k < len; k++ ) {
/* S[ 0 ], S[ 1 ]: Q12 */
inval = in[ k ];
out32_Q14 = SKP_LSHIFT( SKP_SMLAWB( S[ 0 ], B_Q28[ 0 ], inval ), 2 );
S[ 0 ] = S[1] + SKP_RSHIFT_ROUND( SKP_SMULWB( out32_Q14, A0_L_Q28 ), 14 );
S[ 0 ] = SKP_SMLAWB( S[ 0 ], out32_Q14, A0_U_Q28 );
S[ 0 ] = SKP_SMLAWB( S[ 0 ], B_Q28[ 1 ], inval);
S[ 1 ] = SKP_RSHIFT_ROUND( SKP_SMULWB( out32_Q14, A1_L_Q28 ), 14 );
S[ 1 ] = SKP_SMLAWB( S[ 1 ], out32_Q14, A1_U_Q28 );
S[ 1 ] = SKP_SMLAWB( S[ 1 ], B_Q28[ 2 ], inval );
/* Scale back to Q0 and saturate */
out[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT( out32_Q14 + (1<<14) - 1, 14 ) );
}
}
/* even order AR filter */
void SKP_Silk_LPC_synthesis_filter(
const SKP_int16 *in, /* I: excitation signal */
const SKP_int16 *A_Q12, /* I: AR coefficients [Order], between -8_Q0 and 8_Q0 */
const SKP_int32 Gain_Q26, /* I: gain */
SKP_int32 *S, /* I/O: state vector [Order] */
SKP_int16 *out, /* O: output signal */
const SKP_int32 len, /* I: signal length */
const SKP_int Order /* I: filter order, must be even */
)
{
SKP_int k, j, idx, Order_half = SKP_RSHIFT( Order, 1 );
SKP_int32 SA, SB, out32_Q10, out32;
/* Order must be even */
SKP_assert( 2 * Order_half == Order );
/* S[] values are in Q14 */
for( k = 0; k < len; k++ ) {
SA = S[ Order - 1 ];
out32_Q10 = 0;
for( j = 0; j < ( Order_half - 1 ); j++ ) {
idx = SKP_SMULBB( 2, j ) + 1;
SB = S[ Order - 1 - idx ];
S[ Order - 1 - idx ] = SA;
out32_Q10 = SKP_SMLAWB( out32_Q10, SA, A_Q12[ ( j << 1 ) ] );
out32_Q10 = SKP_SMLAWB( out32_Q10, SB, A_Q12[ ( j << 1 ) + 1 ] );
SA = S[ Order - 2 - idx ];
S[ Order - 2 - idx ] = SB;
}
/* unrolled loop: epilog */
SB = S[ 0 ];
S[ 0 ] = SA;
out32_Q10 = SKP_SMLAWB( out32_Q10, SA, A_Q12[ Order - 2 ] );
out32_Q10 = SKP_SMLAWB( out32_Q10, SB, A_Q12[ Order - 1 ] );
/* apply gain to excitation signal and add to prediction */
out32_Q10 = SKP_ADD_SAT32( out32_Q10, SKP_SMULWB( Gain_Q26, in[ k ] ) );
/* scale to Q0 */
out32 = SKP_RSHIFT_ROUND( out32_Q10, 10 );
/* saturate output */
out[ k ] = ( SKP_int16 )SKP_SAT16( out32 );
/* move result into delay line */
S[ Order - 1 ] = SKP_LSHIFT_SAT32( out32_Q10, 4 );
}
}
SKP_INLINE SKP_int16 *SKP_Silk_resampler_private_IIR_FIR_INTERPOL(
SKP_int16 * out, SKP_int16 * buf, SKP_int32 max_index_Q16 , SKP_int32 index_increment_Q16 ){
SKP_int32 index_Q16, res_Q15;
SKP_int16 *buf_ptr;
SKP_int32 table_index;
/* Interpolate upsampled signal and store in output array */
for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
table_index = SKP_SMULWB( index_Q16 & 0xFFFF, 144 );
buf_ptr = &buf[ index_Q16 >> 16 ];
res_Q15 = SKP_SMULBB( buf_ptr[ 0 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 0 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 1 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 1 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 2 ], SKP_Silk_resampler_frac_FIR_144[ table_index ][ 2 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 3 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 2 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 4 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 1 ] );
res_Q15 = SKP_SMLABB( res_Q15, buf_ptr[ 5 ], SKP_Silk_resampler_frac_FIR_144[ 143 - table_index ][ 0 ] );
*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q15, 15 ) );
}
return out;
}
/* Uses SMULL(), available on armv4 */
SKP_int32 SKP_Silk_schur64( /* O: Returns residual energy */
SKP_int32 rc_Q16[], /* O: Reflection coefficients [order] Q16 */
const SKP_int32 c[], /* I: Correlations [order+1] */
SKP_int32 order /* I: Prediction order */
)
{
SKP_int k, n;
SKP_int32 C[ SKP_Silk_MAX_ORDER_LPC + 1 ][ 2 ];
SKP_int32 Ctmp1_Q30, Ctmp2_Q30, rc_tmp_Q31;
/* Check for invalid input */
if( c[ 0 ] <= 0 ) {
SKP_memset( rc_Q16, 0, order * sizeof( SKP_int32 ) );
return 0;
}
for( k = 0; k < order + 1; k++ ) {
C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ];
}
for( k = 0; k < order; k++ ) {
/* Get reflection coefficient: divide two Q30 values and get result in Q31 */
rc_tmp_Q31 = SKP_DIV32_varQ( -C[ k + 1 ][ 0 ], C[ 0 ][ 1 ], 31 );
/* Save the output */
rc_Q16[ k ] = SKP_RSHIFT_ROUND( rc_tmp_Q31, 15 );
/* Update correlations */
for( n = 0; n < order - k; n++ ) {
Ctmp1_Q30 = C[ n + k + 1 ][ 0 ];
Ctmp2_Q30 = C[ n ][ 1 ];
/* Multiply and add the highest int32 */
C[ n + k + 1 ][ 0 ] = Ctmp1_Q30 + SKP_SMMUL( SKP_LSHIFT( Ctmp2_Q30, 1 ), rc_tmp_Q31 );
C[ n ][ 1 ] = Ctmp2_Q30 + SKP_SMMUL( SKP_LSHIFT( Ctmp1_Q30, 1 ), rc_tmp_Q31 );
}
}
return( C[ 0 ][ 1 ] );
}
void SKP_Silk_warped_LPC_analysis_filter_FIX(
SKP_int32 state[], /* I/O State [order + 1] */
SKP_int16 res[], /* O Residual signal [length] */
const SKP_int16 coef_Q13[], /* I Coefficients [order] */
const SKP_int16 input[], /* I Input signal [length] */
const SKP_int16 lambda_Q16, /* I Warping factor */
const SKP_int length, /* I Length of input signal */
const SKP_int order /* I Filter order (even) */
)
{
SKP_int n, i;
SKP_int32 acc_Q11, tmp1, tmp2;
/* Order must be even */
SKP_assert( ( order & 1 ) == 0 );
for( n = 0; n < length; n++ ) {
/* Output of lowpass section */
tmp2 = SKP_SMLAWB( state[ 0 ], state[ 1 ], lambda_Q16 );
state[ 0 ] = SKP_LSHIFT( input[ n ], 14 );
/* Output of allpass section */
tmp1 = SKP_SMLAWB( state[ 1 ], state[ 2 ] - tmp2, lambda_Q16 );
state[ 1 ] = tmp2;
acc_Q11 = SKP_SMULWB( tmp2, coef_Q13[ 0 ] );
/* Loop over allpass sections */
for( i = 2; i < order; i += 2 ) {
/* Output of allpass section */
tmp2 = SKP_SMLAWB( state[ i ], state[ i + 1 ] - tmp1, lambda_Q16 );
state[ i ] = tmp1;
acc_Q11 = SKP_SMLAWB( acc_Q11, tmp1, coef_Q13[ i - 1 ] );
/* Output of allpass section */
tmp1 = SKP_SMLAWB( state[ i + 1 ], state[ i + 2 ] - tmp2, lambda_Q16 );
state[ i + 1 ] = tmp2;
acc_Q11 = SKP_SMLAWB( acc_Q11, tmp2, coef_Q13[ i ] );
}
state[ order ] = tmp1;
acc_Q11 = SKP_SMLAWB( acc_Q11, tmp1, coef_Q13[ order - 1 ] );
res[ n ] = ( SKP_int16 )SKP_SAT16( ( SKP_int32 )input[ n ] - SKP_RSHIFT_ROUND( acc_Q11, 11 ) );
}
}
